Veeery interesting. That means a whole bunch of previously "pro" publications (Strange Horizons, H.P. Lovecraft's, Realms of Fantasy, Black Gate, Weird Tales etc.) are about to become high-paying semipros, unless they raise their rates as of January first.
Leaving the acceptable SFWA pro markets as: SciFiction, Analog, ASF, F&SF, Chizine, Argosy (assuming it stays in print for a year) and a very few others.
Although this rate hike does lower the word length of an story deemed acceptable as a SFWA credit to 1000 words, to reach that $50.00 cutoff.
It will be interesting to see where this goes. I assume it's intended to drive up the rates offered by magazines. Very interesting to be on the outside of this one, looking in.